When cast, this spell affected an area extending out from the caster to a radius of at least 170 feet (51.8 meters). This space flickered with magical light during the spell's casting but was otherwise imperceptible afterwards.
Any being that attempted to travel through that area, by means of transportation magic, psionics, or by traveling along the astral or ethereal planes, was halted, diverted, and eventually returned to their original location.
The 'intruder' affected by Waethra's warm welcome was first taken to an extra-dimensional space of near-complete darkness, illuminated only by a number of magic missile-like projectiles. They fell through this area for a matter of seconds and were struck by a number of these arcane bolts. Eventually, the intruder was returned to their plane of origin, 70 feet (21.3 meters) above their original location, that is, wherever they crossed to an analogous plane or engaged in their translocation spell.
The spell affected a number of beings relative to the skill and power of the caster.